1. Field of the Invention
This invention relates to a semiconductor device in which a channel layer and an electron supply layer are formed on a semi-insulating substrate to use a two-dimensional electron gas.
2. Description of the Related Art
A high electron mobility transistor (HEMT) is a field-effect semiconductor device in which a channel layer and an electron supply layer are formed on a semi-insulating substrate to use carriers called a two-dimensional electron gas.
Generally, HEMT's can operate at high speeds. In addition, HEMT's can generate a high power output. Furthermore, HEMT's have low noise figures.
Prior-art HEMT's have problems as will be indicated later.